Barnes, Greater London
Glazed rear extension in Barnes
Glazed rear extension in Barnes: full-height glass, slim frames and big rooflights for the most open rear room. We measure the house, show you what the rules allow, price it in writing and build it.
Barnes sits in Greater London, with postcode districts including SW13, SW14 and W4. If your garden in Barnes faces south, expect us to talk about overhangs and solar-control glass before frame colours.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a glazed rear extension cost in Barnes?
A glazed rear extension in Barnes is priced at £3,640–£6,240 per square metre including VAT as a guide, before kitchen fit-out and fees. London prices sit at the top of our range because of labour rates, access through the house, parking suspensions and skip licences.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £43,500–£75,000 |
| 4 m wide × 6 m deep (24 m²) | £87,500–£150,000 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a glazed rear extension in Barnes?
The planning route for a glazed rear extension in Barnes is set by England's householder rules and your council.
In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is within 2 metres of a boundary.
New fabric must meet Approved Document L (2021 edition incorporating 2023 amendments): walls 0.18, roof 0.15 and floor 0.18 W/m²K, windows 1.4 W/m²K or Band B. Under the simple route, new windows, doors and rooflights should not exceed 25% of the extension floor area plus any openings removed; more glass is possible with a whole-house calculation.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Barnes like to extend?
Period terraces in Barnes sit alongside flats, and the difference matters: houses usually keep permitted development rights, while flats and maisonettes need planning permission for any rear extension.
How a glazed rear extension in Barnes comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Glazed rear extensions near Barnes
Close by, we work in Mortlake, about 0.9 miles away, and East Sheen, about 1.1 miles away.
- Glazed rear extension in Mortlake
- Glazed rear extension in East Sheen
- Glazed rear extension in Chiswick
- Glazed rear extension in Roehampton
- Glazed rear extension in Putney
Other work in Barnes:
FAQ
Glazed rear extension questions in Barnes
Do you handle building control in Barnes?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
How much does a glazed rear extension cost in Barnes?
As a guide, £3,640–£6,240 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £43,500–£75,000 at that rate. Your written price follows the survey.
Sliding or bifold doors?
Sliders give bigger panes and slimmer sightlines; bifolds open the whole width. Our guide compares them.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
Do I need planning permission for a rear extension in Barnes?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.